Fermentation has been used by mankind for thousands of years for
brewing beer, fermenting wine and raising
bread. The products of the
fermentation
of sugar by baker's yeast Saccharomyces cerevisiae (a
fungus)
are
ethyl alcohol and carbon dioxide. Carbon dioxide causes bread to
rise
and
gives effervescent drinks their bubbles. This action of yeast on
sugar
is
used to 'carbonate' beverages, as in the addition of bubbles to
champagne).
[Note: In response to many questions I have received, here is a discussion of the
small
amount of ethyl alcohol which results in this root
beer .]

We will set up a fermentation in a closed system and capture the
generated
carbon dioxide to carbonate root beer. You may of course adjust
the
quantities
of sugar and/or extract to taste. You should be able to find root
beer extract at your local supermarket. Hires and A&W
have a long history of makiing root beer extract. I find
Zatarain's extract especially delicious, but your definition of
root beer may include a different assortment of flavors. If
you can't find it, Zatarain's,
a product of New Orleans can be ordered on the
web. Other flavors can be
substituted for the root beer extract. Try using a
tablespoon of
vanilla instead of the extract for a cream soda, and grated ginger
and lemon
for ginger
ale.

IMPORTANT
SAFETY
CAUTION: As you follow the following recipe, be
sure to refrigerate these bottle-fermented soft drinks as
soon as
the bottle feels hard. Especially in the
summer, after
a week or so, there is a risk of explosion!

[SUGAR SUBSTITUTES?Many people have emailed
me
asking about
substituting artificial sweeteners for the sugar in this
recipe.
The
short answer is no. Sugar is required for yeast to
generate
carbon
dioxide
which carbonates the beverage. No sugar, no
carbonation.
You
might experiment with less sugar, and add a substitute to make up
for
the
lower sweetness. I do not know how little sugar you can
add and
still get adequate carbonization, but 1/2 cup of sugar/ 2 liters
makes
plenty of carbonation.]

EQUIPMENT

SUPPLIES

clean 2 liter plastic soft drink bottle with cap.
(I do not recommend glass bottles because of the risk of
explosive
shards of glass...)

powdered baker's yeast (1/4 teaspoon) (Yeast for
brewing
would
certainly work at least as well as baking yeast.)

cold fresh water

INSTRUCTIONS:

1) Assemble the necessary equipment and supplies

2) With a dry funnel, add in sequence:

1 level cup of table sugar (cane sugar) (You
can
adjust
the amount to achieve the desired sweetness. Cutting the
sugar in half
still produces adequate carbonation with much less
sweetness.)

[I get MANY questions about an artificially sweetened
version. Know that some sugar is a must for
carbonation, but if you want to reduce sugar to a
tablespoon per 2 liters, and add artificial sweetener,
it is your choice. I confess that I do not trust
artificial sweeteners. Call me a luddite...]

3) Add: 1/4 teaspoon powdered baker's yeast (
fresh and active)

(Fleischmann's or other brand)

Some have suggested that using champagne yeast may produce
less of a yeasty flavor. I don't mind the complexity
of this recipe,. and have not tried varying the yeast
used. If you find a significant improvement with
more esoteric yeasts, let me know.

4) You can see the yeast granules on top of the sugar.

5) Shake to distribute the yeast grains into the sugar.

6) Swirl the sugar/yeast mixture in the bottom to make
it
concave
(to catch the extract).

8) The extract sticks to the sugar which will help
dissolve
the
extract in the next steps. If you shake it, it will
further help it to dissolve.

9) Half fill the bottle with fresh cool tap water (the
less
chlorine,
the better since yeast does not like chlorine). You
can diminish the amount of chlorine by drawing water the
night before, placing in a large pot, and letting it
"exhale" the chlorine overnight.

Rinse in the extract which sticks to the tablespoon and
funnel. Swirl
to
dissolve the ingredients.

10) Q.s. [fill up] to the neck of the bottle
with
fresh
cool tap water, leaving about an inch of head space,
securely screw
cap
down to seal. Invert repeatedly to thoroughly dissolve.

If you leave it in a warm
temperature longer than two weeks,
you
risk an explosion...

11) Place at room temperature (RT)about three to four
days
until
the bottle feels hard to a forceful squeeze. Move to a
cool place
(below
65 F). refrigerate overnight to thoroughly chill before
serving. Crack
the
lid of the thoroughly chilled root beer just a little to
release the
pressure
slowly.

NOTE: Do not leave the finished root beer in a warm
place once the bottle feels hard. After a couple weeks or
so at room
temperature,
especially in the summer when the temperature is high,
enough pressure
may
build up to explode the bottle! There is no danger of this
if the
finished
root beer is refrigerated.

12) Move to a refrigerator overnight before opening.

NOTE: There will be a sediment of yeast at the bottom of
the
bottle,
so that the last bit of root beer will be turbid. It will not hurt
you, but you can decant carefully if
you
wish to avoid this sediment.

A WORD ABOUT THE
ALCOHOL IN
HOME MADE ROOT BEER (OR
GINGER ALE ): I have received numerous
inquiries about
whether
there might be alcohol in this home made soft drink. The answer is
yes,
but... We have tested in our lab the alcoholic content which
results
from the fermentation of this root beer and found it to be between
0.35
and
0.5 %. Comparing this to the 6% in many beers, it would require a
person
to drink about a gallon and a half of this root beer to be
equivalent
to
one 12 ounce beer. I would call this amount of alcohol negligible,
but
for
persons with metabolic problems who cannot metabolize alcohol
properly,
or
religious prohibition against any alcohol,
consumption
should
be limited or avoided. However, there are many high school biology
labs
who
have made this beverage without any problems. If you are one of
these,
I
am interested to hear about your conclusions.